Spintronics devices, which simultaneously exploit the spin and charge of the
electron, are being explored due to promising new electronic applications.
Our devices consist of an aluminum wire contacted with two different
ferromagnets (FM) with different coercive fields, as shown in the
SEM image. Tunnel barriers between the FMs and the Al are grown in
situ using a stencil mask and angle evaporation techniques.
The Al is 100 nm wide while the FMs are 50nm wide and 150 nm apart,
dimensions well below the spin relaxation length of ~300 nm. The
measurements show the spin-valve effect at room temperature for positive
and negative H-field sweep direction, with ~100 times larger signal
than in previous work.